Arduino for STM32

Hi All,

I have played around with the Blue Pill boards for the past six months, and I haven't been too impressed with them. One feature I did like with the integration with Arduino is the ability to use the serial interface inside Arduino for simple debugging. In parallel with this use, I've been doing things with MBED and st-link V2, which gave me a little more flexibility to work around problems I couldn't understand with only Arduino as a basis.

I am attempting to use Arduino with a Black Pill board I've just received. I've done a little work for it with MBED and ST-Link V2 but it would be nice to be able to use the Arduino environment with the 411, especially since the bootstrap doesn't get corrupted every time you turn around.

A YouTube video caught my eye, and the creator recommended the STMduino board package as a source for black pill board drivers which did not register with me previously. I installed the 1.8.0 library but found no support for the 411, the highest being the 407. Looking at the release wiki, I see the 411 listed with a yellow heart and identifying it for version 1.9.0. I looked around a little but didn't see anything suggesting 1.9.0 might be 'soon'.

Is there a date for the release of 1.9.0, or is there a 'development version' of the board file for the Black Pill STM32F411CEU6 that can be had?

I am pretty much a newbie when it comes to GitHub, so there may be a means to do this, so I apologize in advance a potentially dumb question.

Ott

Hi,

The 1.9.0 will be released soon. Currently, I'm doing a full non regression.
I'm also supporting a respirator project for covi19 crisis using the core which delayed this release.
You can use the git repo following this wiki:
https://github.com/stm32duino/wiki/wiki ... repository

Thanks for the response. I'll take a look at that link.

Good on you with the COVID-19 Respirator work!

Ott

(Duplicate of my query on issue #722 - is discussion better here or in the ticket?)

Q1)
I have a question about the STM32F4xx definitions. For example, in Generic_F411Cx/variants.h, it lists one of the pins as:
#define PB9 25 // | 25 | | | TWI1_SDA, (TWI2_SDA) | SPI2_SS | |

However, the documentation from STM clearly states that PB9 is on pin 46 for the 48-pin package. As a matter of fact, pin 25 isn't listed for PB9 for any of the chip packages!

Q2)
In variant.cpp, why is this set to 192, when the STM32F4xx is clocked at 100MHz, not 96MHz?
RCC_OscInitStruct.PLL.PLLN = 192; // VCO output clock = 192 MHz (1 MHz * 192)
(The STM32F401 variant is clocked at 84MHz correctly)

Q1:
There is no link between those number.
25 is the pin number in Arduino world, for generic variant we simply list each GPIO pins in order PA0-15, PB0-1, ...
You can also check other variant, for example a Nucleo have the Arduino connector so the the pin linked to D0 is equal to 0 and in ST documentation its probably have an other number. The simple way is to use the ST pin name PYn.

Q2:
Simply because, USB clock have to be 48MHz and so not possible to have it a 100MHz. Moreover this config is valid for all HSE_value.
Feel free to redefine your own clock config to have 100 MHz. Do not forget it is a generic config so it intends to be as generic as possible.

Ok... so the first question it's more of just an enumeration than actual physical pins?

And I understand with the clock now. I can override these in my sketch to bump it up to 100MHz if needed, no?

Yes you can do your own clock config.

It is a weak function so define your one at sketch level: